Disk graphophone.



T. H. MACDONALD.

DISK GRAPHOPHONE.

APPLIUATIUN ruw rma.

UNITED STATES PATENT OFFICE.

THOMAS H. MACDONALD, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO AMERICAN GRAPHOPHONE COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION OF WEST VIRGINIA.

DISK GRAPHOPHONE.

Specification of Letters Patent.

Patented Nov. 8, 1908.

Application filed February 16, 1907. Serial No. 357,699.

T o all whom it may concern.'

Be it known that I, THOMAS H. MACDON- ALD, a citizen of the United States, and a resident of. the city of Bridgeport, State of Connecticut, have invented a new and useful Improvement in Disk Graphophones, which improvement is fully set forth in the following specification. v i

The invention relates to talking-machines employing records of the disk type, and specifically to that construction known as tone arm, in which a bracket attached to the machine provides a horizontal bearing in which are independently journaled the horn 1nd the hollow arm that carries the sound- The invention consists of the construction and arrangement of parts as hereinafter set forth and claimed, and in modifications and colorable imitations thereof.

My invention will be best understood by reference to the accompanying drawing, which is a side view, partly broken away, illustrating one embodiment of my invention In this drawing 1 represents a portion of the box or casing of the graphophone or other talking-machine, containing the usual motor etc. 2 is the turn-table, and 3 a disk soundrecord carried thereby. 4 is the bracket secured to casing lfand providing, in its upper portion ,5, a horizontal bearing in which the orn 6 is journaled or swiveled so as to be swung horizontally. 7 is,the hollow arm or tone arm/f carrying the sound-box 8 and the Istylus 9, and suitably mounted in the bearing 5, to have vertical as well as horizontal play. The members 6 and 7 are connected to the bracket 4, at the portion 5, in any suitable manner. f

The construction thus far described is old and well-known. It will be observed that, the hollow arm 7 being pivoted at 5 to swing vertically, the weight of the other end of arm 7 and its sound-box 8 is sustained by the oint of the stylus 9, that rests upon the sur ace of disk 3. The object of the present invention is to relieve the stylus and disk of a part of this weight. As one means of accomplishingv this purpose, I fprovide two coacting bearings, one on the bracket 4 and the other on the arm 7, preferably making one of them yielding, whereby a portion of the weight is taken up, and also preferably making one of them, adjustable.

In the drawin s, 10 represents an integral offset from brac et 4, in which is mounted the vertical cylindrical pin 11, preferably of hard steel. A horizontal barrel 12, preferably made integral with the arm 7, carries the springpressed bolt 13 that abuts against pin 11. At the other end of the barrel is the adjusting screw 14, for regulating the tension of the spring. As indicated by line I-I, the axis of pin 11 coincides with the axis upon which arm 7 turns in its horizontal movement; consequently, during every portion of the horizontal movement of the arm upon this axis, its spring-pressed pin 13 is in proper engagement against the concentric cylindrical pin 1 l. By turning screw 14 in or out, the tension of the spring is increased or lessened, and the weight upon the record 3 at the point 9 is lessened or increased, as the case may be. l

Of course the spring-pressed member, or

yother yielding device might be carried u on the bracket-arm 4,'instead of upon the iol low arm 7, and the adjusting clement might be'upon arm 7 or the parts might in other respects be altered in construction or in arrangement, without departing from the spirit of my invention, which consists of providing means for taking up a portion of the weight of the hollow arm 'so as to relieve the sound-record therefrom; in providing yielding means for this urpose; whereby any inequalities in the p ane suiface of the disk record 3 may be compensated for; and in making this means adjust-able. By thus re'- lieving the record 3 of weight, the hollow arm 7 or the soundbox, or both, may be made of iron or other cheap or convenient metal, in place of aluminum now commonly employed or this purpose. Having thus claim:

1. In a talking-machine, the combination with a bracket, and the hollow arm secured described my inwntion, l L

in said bracket to carry the sound-box, of a j device carried by said bracket, and a second.

device carried by said arnr and abutting against said first-named dcv icc who re l y a portion of the weight of said arm is sus! aiiied,- said second device being both adjustable and also yielding when held in any position of i adjustment. v 2. In a talking-machine, the combination with a bracket, and the hollow arm secured in said bracket to carry the sound-box, of a vertical cylindrical in carried by said bracket in the axis o the horizontal movement of said hollow arm, a sprin -pressed horizontal pin carried by said hol ow arm and abutting against said vertical pin, and an adjusting nut for regulating the tension of the s ring.

3. n a talking-machine, the combination with a bracket and an arm mounted thereupon and carrying the sound-box, of a convex bearing-surface upon said bracket, and a yielding dev-ice carrled on said arm and abutting against said convex surface.

4. In a talking-machine, the combination with a bracket, and an arm mounted thereupon and carrying the sound-box, of a convex bearing-surface upon said bracket concentric With the swing of said arm, and an adjustable device carried upon said arm and abutting against said convex surface. f

5. In a talking-machine, the combination with a bracket, and an arm mounted thereupon to swing in a horizontal plane and carrying the sound-box, of two abutting bearings carried respectively by the bracket and arm aforesaid, one of the said bearings being both adjustable and also yielding when held in adjusted position.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

THOMAS H. MACDONALD. Witnesses: f-

A. B. KEOUGH, C. A. GIBNER. 

